First of all, sorry if my english is not perfect (live in the Netherlands). Well.. My iphone 4 got stolen 3 weeks after it got bought. This sucked obviously.. Through a second hand website I bought a second hand one. It was claimed to be unlocked etc. I visited the guy that wanted to sell it and it looked great. It worked fine and I bought it. When I arrived home I reset it (still had some songs and random other stuff on it) and it automatically updated the iphone. Mobile phone restarted and I couldn't wait to enjoy my new phone. And then (while setting it up) I received a disastrous message. 'Only compatible SIM cards from a supported carrier may be used to activate iPHone. Please insert the SIM card that came with your iPHone or visit a supported carrier's store to receive a replacement SIM card' This confused me, obviously. I sent an email to that guy to which he guiltily replied that it was actually AT&T locked. He jailbreaked it and 'hid' cydia. I know that there is no decent ios5 jailbreak yet. But is there a way to revert to ios 4? Since it is now pretty much a useless phone. Any other ideas would be great. Thanks in advance!